Analysis of the Stem-fillet blend fracture of exhaust valve was conducted by means of macroexamination, microstructure examination, chemical composition analysis and hardness test.

摘要宏、微观检、成分分和硬度测试等方法对断头的排气门进行了分。

Research on the failure reasons of the cooling tube were carried out by means of macroexamination, thickness measurement, X ray diffraction, optical microscopy and chemical analysis.

宏、微观分、成分分等手段,对冷却水管的腐蚀穿孔进行了失效分。